Pressure Effect on Ferromagnetic Transition and Charge-Transfer Phase Transition in a Mixed-Valence Iron Complex (n-C 3 H 7 ) 4 N[Fe II Fe III (dto) 3 ](dto=C 2 O 2 S 2 )
Pressure Effect on Ferromagnetic Transition and Charge-Transfer Phase Transition in a Mixed-Valence Iron Complex (n-C 3 H 7 ) 4 N[Fe II Fe III (dto) 3 ](dto=C 2 O 2 S 2 )
复制标题
压力对混合价铁络合物(n-C 3 H 7 ) 4 N[Fe II Fe III (dto) 3 ](dto=C 2 O 2 S 2 )铁磁相变和电荷转移相变的影响
DOI：
10.1080/713738653
复制
发表时间：
2002
影响因子：
0.7
通讯作者：
K. Asai
中科院分区：
文献类型：
--
作者：
M. Itoi;N. Kojima;Y. Kobayashi;K. Asai
铁的混合价配合物（n-C3 H7）4 N[Fe II Fe III（dto）3 ]（dto= C2 O2 S2）不仅在6.5K发生铁磁相变，而且在120 K附近发生Fe II和Fe III之间的电荷转移相变。为了阐明电荷转移相变的机制，我们测量了外压下的磁化率。在流体静压下，电荷转移转变的临界温度强烈地依赖于外部压力，而居里温度保持不变。另一方面，在0.6 GPa的单轴应力下，居里温度增加到15 K，而电荷转移温度保持不变。释放单轴应力后，常压下的零场磁化强度在7 K和15 K处出现两个峰值，表明Fe Ⅲ（S=5/2），Fe Ⅱ（S=0）和Fe Ⅲ（S=1/2），Fe Ⅱ（s=2）两种铁磁自旋组态共存。在常压下还观察到（n-C4 H9）4 N[Fe Ⅱ Fe Ⅲ（dto）3 ]的两种铁磁自旋组态共存.混合价自旋交叉电荷转移压力效应
Iron mixed-valence complex (n-C 3 H 7 ) 4 N[Fe II Fe III (dto) 3 ] (dto=C 2 O 2 S 2 ) exhibits not only the ferromagnetic transition at 6.5 K but also the charge-transfer phase transition between Fe II and Fe III around 120 K. In order to elucidate the mechanism of the charge-transfer phase transition, we measured the magnetic susceptibility under external pressure. Under hydrostatic pressure up to 0.9 Gpa, the critical temperature of the charge-transfer transition strongly depends on external pressure, while the Curie temperature remains unchanged. Under uniaxial stress of 0.6 GPa, on the other hands, the Curie temperature increases up to 15 K, while the charge-transfer temperature remains unchanged. After releasing uniaxial stress, the zero field magnetization at ambient pressure has two peaks at 7 K and 15 K, which implies two kinds of ferromagnetic spin configuration coexist, i.e. Fe III (S=5/2), Fe II (S=0) and Fe III (S=1/2), Fe II (s=2). The coexistence of two kinds of ferromagnetic spin configuration was also observed for (n-C 4 H 9 ) 4 N[Fe II Fe III (dto) 3 ] at ambient pressure. mixed-valence spin crossover charge transfer pressure effect